The .sis (Software Installation Script) is an installation archive used by the Symbian operating system. Contrary to what many users believe, a .sis extension file is an installation file for the Symbian operating system and not an application file. The main function of .sis file format is to store various files in one installation file that is used to install software on devices that use the Symbian operating system.

To achieve this, transfer the .sis file to your phone using the phone’s communication software. For example, you need to transfer the file to your Nokia phone using Nokia PC Suite. Next, open the .sis file on your phone and follow the instructions to complete the installation.

How to open a .sis file

If you use Windows, you can open a .sis file using the following applications:

UnSIS

Palm OS Emulator.

If you use a Mac Operating System, you can open a .sis file using the following application:

Palm OS Emulator

Is the .sis file extension used by malware programs?

Malware programs are known to use various file extensions, including the .sis file extension to spread and infect an unprotected device. For instance, the file CARIBE.SIS (it contains the following components – CARIBE.APP, FLO.MDL, and CARIBE.RSC) is recorded as a worm, named Symb/Cabir-A). To prevent these infections to your computer as well as your mobile device, it is essential that you protect them with a reliable security suite.

In case you are unable to open a .sis file on your computer then it is recommended that you use an efficient file repair software for quick access to the file.